21372832 has 48 divisors (see below), whose sum is σ = 45934560. Its totient is φ = 9729792.

The previous prime is 21372811. The next prime is 21372839. The reversal of 21372832 is 23827312.

It is a self number, because there is not a number n which added to its sum of digits gives 21372832.

It is not an unprimeable number, because it can be changed into a prime (21372839) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 34219 + ... + 34837.

It is an arithmetic number, because the mean of its divisors is an integer number (956970).

Almost surely, 2^21372832 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21372832, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22967280).

21372832 is an abundant number, since it is smaller than the sum of its proper divisors (24561728).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21372832 is a wasteful number, since it uses less digits than its factorization.

21372832 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 725 (or 717 counting only the distinct ones).

The product of its digits is 4032, while the sum is 28.

The square root of 21372832 is about 4623.0760322538. The cubic root of 21372832 is about 277.5155719963.

The spelling of 21372832 in words is "twenty-one million, three hundred seventy-two thousand, eight hundred thirty-two".